TUNNELING

The excavation of tunnels in loose soils or in presence of crumbly or glacial formations requires the use of preventive consolidations in the vault and, if necessary, in the piers. Over the last years, a technique that has been widely adopted is the one involving "pre-reinforcement during advance excavation", also called R.P.U.M. (Reinforced Protective Umbrella Method).

Trevi, which has been active in this sector since 1985, uses two patented products: TREVITUB and SPRINGVAL. The TREVITUB technique is particularly suitable for executing forepilings in glacial or coarse soils, with the presence of blocks and erratics. Said technique consists in installing, by roto-percussion drilling, a sufficient number of steel pipes equipped with special non-return valves for the following grouting. In case of cased drilling (ODEX system or the like), the casing could be abandoned in the hole and, for this reason, the pipe is equipped with SPRINGVAL, i.e. special patented valves drilled and installed into the pipe's thickness, and such as not to undergo damages during the penetration into the soil.